Out-of-Pocket Costs and Oral Cancer Medication Discontinuation in the Elderly

BACKGROUND: Cancer is a major cause of mortality and a major contributor to health care costs in the United States. An increasing number of cancer patients are treated with oral cancer therapy. Older patients are more likely to have cancer and to be at risk for adherence problems with oral cancer drugs. As a result of substantial cost sharing required for oral cancer drugs and the possibility of early entry into the Medicare Part D coverage gap, high out-of-pocket (OOP) drug costs could put elderly beneficiaries at great risk for delaying or discontinuing their cancer therapies. OBJECTIVES: To (a) determine the OOP costs of oral cancer treatment and the numbers of patients that delay or discontinue oral cancer therapy and (b) examine the relationship between OOP costs and medication discontinuation or delay among older Medicare beneficiaries. METHODS: A cross-sectional study was conducted using a 5% sample of Medicare beneficiaries who filled a prescription for imatinib, erlotinib, anastrozole, letrozole, or thalidomide during 2008. Patients included in the analysis sample did not receive drug subsidies, were aged 65 years or older, and were enrolled in Medicare Part D for all 12 months of 2008. Logistic regression was used to determine the association between OOP costs and medication discontinuation or delay. RESULTS: Mean OOP costs per day were $2.96 for anastrozole, $3.10 for letrozole, $22.90 for imatinib, $28.35 for erlotinib, and $37.47 for thalidomide. The percentages of patients who discontinued or delayed oral cancer therapy were 58% for anastrozole, 64% for letrozole, 35% for imatinib, 61% for erlotinib, and 70% for thalidomide. For each $10 increase in OOP spending per month, the likelihood of discontinuation or delay increased 13%, 14%, and 20% for imatinib, erlotinib, and thalidomide users, respectively, but decreased 26% for anastrozole and letrozole users. CONCLUSIONS: Beneficiaries with higher OOP costs for the more expensive oral cancer drugs were more likely to discontinue or delay drug therapy.